Mine works a treat and cost $25 all up, the dia inlet has to be at least 40mm ID, you can use a boat skin fitting or a 90deg PVC bend glued in with sikaflex, the inlet must have a small deflector above the outlet inside the air box so it does not blow directly at one spot of the filter, also stops water mist at high speed spraying directly on the filter.
A circular bit of "anything flat" held to the PVC with a couple of home made brackets and some rivets or whatever and your done, but to do it justice the large inlet from the T/B needs to be insulated from the header's heat, or all your doing is giving it more hot air, not cold air, or it's a HAI not a true CAI.
Once the bend is secured and dry you can scab up the vacum cleaner hose, a hose clamp at each end and a few cable clamps to keep the hose hard against the guard, hooks up to the brake duct inlet of the VS bumper.
The hose must be flush with the guard, paint it black, add a quick drive on a dusty road and it's near invisible, but in the odd chance that a bird got stuck in the inlet, about 1,000,000/1 odds, the original GM CAI can be left there, cook the bird later.
Oh yeah, 6.4 lit / 100 km on the highway. so it works fine.
